Plastic pollution threatens Lake Malawi’s unique fish

Lake Malawi, one of Africa’s most important freshwater ecosystems and a UNESCO World Heritage Site, is under growing threat from plastic pollution — endangering both its extraordinary biodiversity and the communities that depend on it.

Home to more than a thousand species of cichlid fish found nowhere else on Earth, the lake is considered by UNESCO to be as important to evolutionary science as the Galapagos Islands. But researchers and conservationists warn that plastic waste accumulating on the lakebed is disrupting fish breeding, contaminating the food chain and tarnishing the lake’s appeal to tourists.

Evolutionary biologist Professor Kenneth McKaye, who has studied Lake Malawi’s cichlids since 1977, says plastic pollution is increasingly interfering with fish reproduction and posing risks to human health.

“Garbage can come on the breeding platforms, or in the territories, of the males. It makes it difficult for the fish to breed,” McKaye explains. “The fish can ingest not only full plastic, but also the microplastic. And the plastics are breaking down in the lake, people are drinking it, so they’re going to be getting microplastics.”

While targeted clean-ups can help protect specific tourist areas, McKaye stresses that the long-term solution lies in policy change. “What is necessary is to stop the single-use plastics in Malawi, and follow the example of other countries such as Tanzania and Kenya,” he says.

At the frontline of the clean-up effort is a local team of divers working with the NGO HEEED — Health, Education, Environment and Economic Development — based in Cape Maclear. The team conducts regular underwater clean-ups, removing plastic bottles, bags and other debris from the lake floor.

Divemaster Felix Sinosi says underwater pollution not only harms wildlife but also damages the tourism experience. “The garbage that is underwater seems useless. But it is destructive,” he says. “When diving tourists come here with cameras to see fish, instead they see garbage underwater, which is not good.”

The problem goes beyond aesthetics. “Fish eat plastic and this also affects humans, as humans eat fish,” Sinosi adds.

Collected waste is not simply discarded. Some of it is repurposed through upcycling initiatives that provide livelihoods for local residents. Garbage diver Fishani Choice is part of a team that transforms recovered waste into craft products sold to visitors.

“We dive three times a week to clean up the lake,” Choice says. “We collect garbage like glass bottles, plastic bottles, plastic bags, tins. We work with these items to recycle them into crafts.”

Despite Malawi producing tens of thousands of tonnes of plastic annually — most of it single-use — the country lacks government-run recycling facilities, allowing waste to be blown or washed into the lake. Pollution from neighboring countries that share Lake Malawi also contributes to the problem.

For conservationists, the message is clear: while community-led clean-ups are making a visible difference, protecting one of the world’s most remarkable freshwater ecosystems will ultimately require stronger enforcement of plastic bans and a decisive move away from single-use plastics.